Electronic devices such as thin film transistor type active matrix LCD (TFT-LCD) are used in various applications such as car navigations, digital camera finders, and in addition, personal computer monitors and television sets, because the electron devices are thin and need small electric power consumption.
In general, aluminoborosilicate glasses containing substantially no alkali metal oxide are used as materials of a glass substrate for TFT-LCD, and there are various glass compositions suggested until now (see Patent Documents 1 to 3).
TFT-LCD panel manufacturers try to improve productivity and decrease cost by producing a plurality of devices on a glass substrate (rough plate) which are formed by glass manufacturers, then, cutting the substrate to divide into respective devices, and collecting a product. Recently, the screen sizes of personal computer monitors, television sets, and the like has been enlarged, thus, a large-sized glass substrate is required for multiple production of those devices.
[Patent Document 1] JP 2990379 B
[Patent Document 2] JP 3465238 B
[Patent Document 3] JP 2002-29775 A